A must-have app for any Calc Student

Its funny how we pay thousands of dollars to take this class in college and this app explains literally everything Ive covered so far (and with helpful animations) for only $2.99. I usually shy away from paid apps, however if you are looking for a study resource for Calc I, this is your best bet for sure.
I am not sure if there is a "Calc II FTW" app out there or possibly in the making but I pray there is before next semester comes around.

NBCloper about Calculus FTW - Deep Insight into Solving Calculus Problems